
const fp = require('loadsh/fp');
const { Maybe, Container } = require('./support');

// 练习1
let maybe = Maybe.of([5, 6, 1]);
let ex1 = () => {
    return maybe.map(fp.map(fp.add(1)))
}
console.log(ex1());


// 练习2
let xs = Container.of(['do', 'ray', 'me', 'fa', 'so', 'la', 'ti', 'do']);
let ex2 = () => {
    return xs.map(fp.first)
}
console.log(ex2());

// 练习3
let safeProp = fp.curry(function (x, o) {
    return Maybe.of(o[x]);
})
let user = { id: 2, name: 'Albert' }
let ex3 = () => {
    return safeProp('name', user).map(fp.first)
}
console.log(ex3());

// 练习4
// let ex4 = function (n) {
//     if (n) {
//         return parseInt(n);
//     }
// }
let ex4 = n => {
    return Maybe.of(n).map(parseInt)._value;
}
console.log(ex4(2.3))